Lock worksheet cells in C# (in owc11)

Hi 
I set a Spreadsheet control on a container, using Office Web Components 11 (Office 2003).  However, I need to lock a range of cells to prevent the user from editing them.  I tried:
_workBook.axSpreadsheet1.ActiveSheet.Range["B4", Missing.Value].Locked = true; But I get the following error:
Property, indexer, or event 'Locked' is not supported by the language; try directly calling accessor methods 'Microsoft.Office.Interop.Owc11._Range.get_Locked()'
The equivalent VB code should work, but I need to do it in C#.  I can't find the answer.  Does anyone know a workaround?
Thanks
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